From £36,6858
Do larger dimensions and return to fabric roof make mid-sized open-top a more appealing proposition?
2 March 2021

What is it?

So, it’s back to fabric: BMW has retired the folding metal roof that appeared first on the 3 Series Convertible in 2004 and then in modified form on the 4 Series Convertible in 2014.

The new second-generation 4 Series Convertible adopts a traditional hood, and with it arguably more appealing proportions that have added a generous 128mm to its length and 27mm to its width while contributing to a 10mm reduction in height at a respective 4768mm, 1852mm and 1384mm.

This doesn’t come as a surprise: both the smaller 2 Series Convertible and larger 8 Series Convertible have fabric roofs, so it was really only a matter of time.

The exterior design is dominated by the large, vertically stacked grille – as first seen on the 4 Series Coupé and set to be adopted by the upcoming 4 Series Gran Coupé. The bolder front end undoubtedly gives the new 4 Series Convertible greater visual presence, although it's somewhat at odds with the car's otherwise svelte lines.

The multi-layer fabric roof, developed specifically for the 4 Series Convertible, is claimed to be 40% lighter than the old metal item. It opens automatically and stows beneath a plastic tonneau cover behind the rear seats in the upper part of the boot. The whole process takes just 18sec and can be done while the car is moving at speeds up to 31mph.

The packaging of the new structure is greatly improved, leading to a slight increase in head room for front-seat occupants and a larger boot. With the roof down, there's 80 litres more luggage space than before, at 300-litres. This increases to 385 litres – 15 litres more than before – when the roof is closed and a retaining function is manually folded back. A folding rear centre backrest and through-loading function is standard on all models.

As with its coupé sibling, the 4 Series Convertible is based on the latest evolution of BMW’s CLAR (cluster architecture) platform. It receives a 41mm longer wheelbase than its predecessor, at 2851mm, as well as track widths increased by 28mm to 1575mm at the front and by 18mm to 1611mm at the rear.

To offset the lack of a fixed roof structure, BMW has added bracing to a front and rear bulkheads and within the floorpan to boost stiffness and rigidity.

Inside, there’s a new dashboard featuring digital instruments and a heavily upgraded infotainment system with BMW’s latest ID7 operating system. Quality has taken a big step in line with developments brought to the 4 Series Coupé.

The UK line-up at launch comprises five models: the petrol 420i and M440i xDrive, plus the 420d, 430d and M440d xDrive diesels. Standard models receive rear-wheel drive, while the M Performance models feature four-wheel drive.

Advertisement
Advertisement

Find an Autocar review

Back to top

What's it like?

The turbocharged 3.0-litre in-line six-cylinder petrol engine in the M440i Convertible driven here adopts 48V mild-hybrid technology and develops 369bhp and 369lb ft of torque between 1900rpm and 5000rpm.

Mated to a smooth and quick-shifting eight-speed automatic gearbox as standard, it delivers crisp throttle response and strong in-gear urge with a typical willingness to rev when the conditions allow. But it's its relaxed part-throttle cruising qualities and outstanding refinement that matter more here.

This is an agreeably comfortable car, with a cabin that provides greater room up front than its predecessor together with adequate – if quite upright – seats in the rear. With the roof down and the folding wind blocker in place behind the front seats and the windows up, there's minimal wind buffeting up to 60mph.  

Performance isn't quite as sharp as that of the M440i Coupé, owing to the 150kg weight penalty brought on by the Convertible’s structural strengthening measures, but a 0-62mph time of 4.9sec and an (electronically limited) 155mph top speed aren't to be sneezed at.

You can sense a moderate loss of rigidity in the body structure through a slighty less direct steering feel and the odd shimmy over undulating roads, but it's still highly enjoyable to drive and quite sharp when running in Sport mode. Thanks to the four-wheel drive, both grip and traction are in abundance.

With optional adaptive dampers helping to boost absorption of the double-wishbone and multi-link suspension, the M440i Convertible also rides quite well, despite the 225/40 and 255/35 19in tyres fitted and lowered M Sport suspension fitted to our test car.

It sometimes quakes over big transverse ruts and deep potholes, but the car is otherwise agreeably subtle and settles well in Comfort mode when it's challenged by an irregular road surface.

Back to top

Should I buy one?

The new 4 Series Convertible represents something of a reset for BMW’s mid-range open-top. The return to a fabric roof provides it with added visual appeal, while the larger dimensions help to make it roomier and a good degree more versatile than the old model.

BMW argues that it also offers a driving experience close to that of the excellent new 4 Series Coupé, and while we wouldn’t go that far, it's clearly more accomplished than before in this respect.

As appealing as the outright pace and agreeable dynamic properties of the £59,645 M440i xDrive Convertible are, though, the better buy is likely to be further down the line-up, in the less powerful, less aggressively shod and rear-wheel-drive 420i, 420d and 430d models.

Join the debate

Comments
1
Add a comment…
Will86 3 March 2021

I think the reviewer nails the grille issue succinctly, it's at odds with the styling of the rest of the car. To my eyes it looks like an afterthought. If BMW want to create striking or controversial designs, appending a dodgy grille to an otherwise reasonably elegant design isn't the way to do it. 

Find an Autocar car review